Physical uplink control channel (PUCCH) resource allocation

ABSTRACT

Certain aspects of the present disclosure relate to methods and apparatus for resource allocation for physical uplink control channel (PUCCH) used to carry uplink control information (UCI). Certain aspects provide a method for wireless communication by a user equipment. The method generally includes receiving downlink control information (DCI) comprising one or more resource indicator (RI) bits configured to indicate to the user equipment a subset of resources available for transmitting UCI in a PUCCH transmission, wherein the DCI is received on one or more resources of a first physical downlink control channel (PDCCH) transmission. The method further includes identifying resources within the subset indicated by the RI bits to transmit the UCI based on an implicit mapping of PDCCH resources to PUCCH resources and the one or more resources of the first PDCCH transmission. The method further includes transmitting the UCI using the identified resources.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent No.62/593,866, filed Dec. 1, 2017. The content of the provisionalapplication is hereby incorporated by reference in its entirety.

BACKGROUND Field of the Disclosure

The present disclosure relates generally to communication systems and tomethods and apparatus for resource allocation for physical uplinkcontrol channel (PUCCH) transmissions.

Description of Related Art

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includeLong Term Evolution (LTE) systems, code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

In some examples, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipment (UEs). In LTE or LTE-A network, a set of one or more basestations may define an eNodeB (eNB). In other examples (e.g., in a nextgeneration or 5G network), a wireless multiple access communicationsystem may include a number of distributed units (DUs) (e.g., edge units(EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs),transmission reception points (TRPs), etc.) in communication with anumber of central units (CUs) (e.g., central nodes (CNs), access nodecontrollers (ANCs), etc.), where a set of one or more distributed units,in communication with a central unit, may define an access node (e.g., anew radio base station (NR BS), a new radio node-B (NR NB), a networknode, 5G NB, eNB, etc.). A base station or DU may communicate with a setof UEs on downlink channels (e.g., for transmissions from a base stationor to a UE) and uplink channels (e.g., for transmissions from a UE to abase station or distributed unit).

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is new radio (NR), for example, 5G radioaccess. NR is a set of enhancements to the LTE mobile standardpromulgated by Third Generation Partnership Project (3GPP). It isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingOFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink(UL) as well as support beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

BRIEF SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Aspects generally include methods, apparatus, systems, computer readablemediums, and processing systems, as substantially described herein withreference to and as illustrated by the accompanying drawings.

Certain aspects provide a method for wireless communication by a UE. Themethod generally includes receiving downlink control information (DCI)comprising one or more resource indicator (RI) bits configured toindicate to the user equipment a subset of resources available fortransmitting uplink control information (UCI) in a physical uplinkcontrol channel (PUCCH) transmission, wherein the DCI is received on oneor more resources of a first physical downlink control channel (PDCCH)transmission. The method further includes identifying resources withinthe subset indicated by the RI bits to transmit the UCI based on animplicit mapping of PDCCH resources to PUCCH resources and the one ormore resources of the first PDCCH transmission. The method furtherincludes transmitting the UCI using the identified resources.

Certain aspects provide a method for wireless communication by a UE. Themethod generally includes receiving, from a base station, an uplinkgrant comprising one or more downlink assignment index (DAI) bits. Themethod further includes determining a number of bits to use to transmitan acknowledgement (ACK) based on the DAI bits. The method furtherincludes transmitting, to the base station, the ACK using the determinednumber of bits.

Certain aspects provide a method for wireless communication by a networkentity. The method generally includes transmitting downlink controlinformation (DCI) comprising one or more resource indicator (RI) bitsconfigured to indicate to a user equipment a subset of resourcesavailable for transmitting uplink control information (UCI) in aphysical uplink control channel (PUCCH) transmission, wherein the DCI istransmitted on one or more resources of a first physical downlinkcontrol channel (PDCCH) transmission. The method further includesidentifying resources within the subset indicated by the RI bits tomonitor for the UCI based on an implicit mapping of PDCCH resources toPUCCH resources and the one or more resources of the first PDCCHtransmission. The method further includes monitoring the identifiedresources for the UCI.

Certain aspects provide a method for wireless communication by a networkentity. The method generally includes transmitting, to a user equipment,an uplink grant comprising one or more downlink assignment index (DAI)bits indicating a number of bits for the user equipment to use totransmit an acknowledgement (ACK) based on the DAI bits. The methodfurther includes receiving, from the user equipment, the ACK using thenumber of bits.

Certain aspects provide a user equipment comprising a memory and aprocessor coupled to the memory. The processor is configured to receivedownlink control information (DCI) comprising one or more resourceindicator (RI) bits configured to indicate to the user equipment asubset of resources available for transmitting uplink controlinformation (UCI) in a physical uplink control channel (PUCCH)transmission, wherein the DCI is received on one or more resources of afirst physical downlink control channel (PDCCH) transmission. Theprocessor is further configured to identify resources within the subsetindicated by the RI bits to transmit the UCI based on an implicitmapping of PDCCH resources to PUCCH resources and the one or moreresources of the first PDCCH transmission. The processor is furtherconfigured to transmit the UCI using the identified resources.

Certain aspects provide a user equipment comprising a memory and aprocessor coupled to the memory. The processor is configured to receive,from a base station, an uplink grant comprising one or more downlinkassignment index (DAI) bits. The processor is further configured todetermine a number of bits to use to transmit an acknowledgement (ACK)based on the DAI bits.

Certain aspects provide a network entity comprising a memory and aprocessor coupled to the memory. The processor is further configured totransmit downlink control information (DCI) comprising one or moreresource indicator (RI) bits configured to indicate to a user equipmenta subset of resources available for transmitting uplink controlinformation (UCI) in a physical uplink control channel (PUCCH)transmission, wherein the DCI is transmitted on one or more resources ofa first physical downlink control channel (PDCCH) transmission. Theprocessor is further configured to identify resources within the subsetindicated by the RI bits to monitor for the UCI based on an implicitmapping of PDCCH resources to PUCCH resources and the one or moreresources of the first PDCCH transmission. The processor is furtherconfigured to monitor the identified resources for the UCI.

Certain aspects provide a network entity comprising a memory and aprocessor coupled to the memory. The processor is configured totransmit, to a user equipment, an uplink grant comprising one or moredownlink assignment index (DAI) bits indicating a number of bits for theuser equipment to use to transmit an acknowledgement (ACK) based on theDAI bits. The processor is further configured to receive, from the userequipment, the ACK using the number of bits.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, in accordance with certain aspects of thepresent disclosure.

FIG. 2 is a block diagram illustrating an example logical architectureof a distributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 3 is a diagram illustrating an example physical architecture of adistributed RAN, in accordance with certain aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample BS and user equipment (UE), in accordance with certain aspectsof the present disclosure.

FIG. 5 is a diagram showing examples for implementing a communicationprotocol stack, in accordance with certain aspects of the presentdisclosure.

FIG. 6 illustrates an example of a DL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIG. 7 illustrates an example of an UL-centric subframe, in accordancewith certain aspects of the present disclosure.

FIGS. 8 a and 8 b illustrate example uplink and downlink structures,respectively, in accordance with certain aspects of the presentdisclosure.

FIG. 9 illustrates example operations for wireless communications by anetwork entity, in accordance with certain aspects of the presentdisclosure.

FIG. 10 illustrates example operations for wireless communications by auser equipment, in accordance with certain aspects of the presentdisclosure.

FIG. 11 illustrates an example of resource allocation for a physicaluplink control channel (PUCCH) transmission, in accordance with certainaspects of the present disclosure.

FIG. 12 illustrates a communications device that may include variouscomponents configured to perform operations for the techniques disclosedherein in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to methods and apparatus fordetermining resources allocated for transmitting uplink controlinformation in a physical uplink control channel (PUCCH).

NR may support various wireless communication services, such as Enhancedmobile broadband (eMBB) targeting wide bandwidth (e.g. 80 MHz beyond),millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHz),massive MTC (mMTC) targeting non-backward compatible MTC techniques,and/or mission critical targeting ultra-reliable low latencycommunications (URLLC). These services may include latency andreliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the samesubframe.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

The techniques described herein may be used for various wirelesscommunication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). NRis an emerging wireless communications technology under development inconjunction with the 5G Technology Forum (5GTF). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that useE-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies. For clarity, while aspects may be describedherein using terminology commonly associated with 3G and/or 4G wirelesstechnologies, aspects of the present disclosure can be applied in othergeneration-based communication systems, such as 5G and later, includingNR technologies.

Example Wireless Communications System

FIG. 1 illustrates an example wireless network 100, such as a new radio(NR) or 5G network, in which aspects of the present disclosure may beperformed.

As illustrated in FIG. 1 , the wireless network 100 may include a numberof BSs 110 and other network entities. A BS may be a station thatcommunicates with UEs. Each BS 110 may provide communication coveragefor a particular geographic area. In 3GPP, the term “cell” can refer toa coverage area of a Node B and/or a Node B subsystem serving thiscoverage area, depending on the context in which the term is used. In NRsystems, the term “cell” and eNB, Node B, 5G NB, AP, NR BS, NR BS, orTRP may be interchangeable. In some examples, a cell may not necessarilybe stationary, and the geographic area of the cell may move according tothe location of a mobile base station. In some examples, the basestations may be interconnected to one another and/or to one or moreother base stations or network nodes (not shown) in the wireless network100 through various types of backhaul interfaces such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a frequencychannel, etc. Each frequency may support a single RAT in a givengeographic area in order to avoid interference between wireless networksof different RATs. In some cases, NR or 5G RAT networks may be deployed.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG), UEs for users in the home,etc.). A BS for a macro cell may be referred to as a macro BS. A BS fora pico cell may be referred to as a pico BS. A BS for a femto cell maybe referred to as a femto BS or a home BS. In the example shown in FIG.1 , the BSs 110 a, 110 b and 110 c may be macro BSs for the macro cells102 a, 102 b and 102 c, respectively. The BS 110 x may be a pico BS fora pico cell 102 x. The BSs 110 y and 110 z may be femto BS for the femtocells 102 y and 102 z, respectively. A BS may support one or multiple(e.g., three) cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a BS or a UE) and sends atransmission of the data and/or other information to a downstreamstation (e.g., a UE or a BS). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1 , arelay station 110 r may communicate with the BS 110 a and a UE 120 r inorder to facilitate communication between the BS 110 a and the UE 120 r.A relay station may also be referred to as a relay BS, a relay, etc.

The wireless network 100 may be a heterogeneous network that includesBSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc.These different types of BSs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro BS may have a high transmitpower level (e.g., 20 Watts) whereas pico BS, femto BS, and relays mayhave a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the BSs may have similar frametiming, and transmissions from different BSs may be approximatelyaligned in time. For asynchronous operation, the BSs may have differentframe timing, and transmissions from different BSs may not be aligned intime. The techniques described herein may be used for both synchronousand asynchronous operation.

A network controller 130 may be coupled to a set of BSs and providecoordination and control for these BSs. The network controller 130 maycommunicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another, e.g., directly or indirectly via wirelessor wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a mobile station, a terminal, an access terminal,a subscriber unit, a station, a Customer Premises Equipment (CPE), acellular phone, a smart phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, a medical device or medical equipment, a biometricsensor/device, a wearable device such as a smart watch, smart clothing,smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, asmart bracelet, etc.), an entertainment device (e.g., a music device, avideo device, a satellite radio, etc.), a vehicular component or sensor,a smart meter/sensor, industrial manufacturing equipment, a globalpositioning system device, or any other suitable device that isconfigured to communicate via a wireless or wired medium. Some UEs maybe considered evolved or machine-type communication (MTC) devices orevolved MTC (eMTC) devices. MTC and eMTC UEs include, for example,robots, drones, remote devices, sensors, meters, monitors, locationtags, etc., that may communicate with a BS, another device (e.g., remotedevice), or some other entity. A wireless node may provide, for example,connectivity for or to a network (e.g., a wide area network such asInternet or a cellular network) via a wired or wireless communicationlink. Some UEs may be considered Internet-of-Things (IoT) devices. InFIG. 1 , a solid line with double arrows indicates desired transmissionsbetween a UE and a serving BS, which is a BS designated to serve the UEon the downlink and/or uplink. A dashed line with double arrowsindicates interfering transmissions between a UE and a BS.

Certain wireless networks (e.g., LTE) utilize orthogonal frequencydivision multiplexing (OFDM) on the downlink and single-carrierfrequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a ‘resource block’) may be 12 subcarriers(or 180 kHz). Consequently, the nominal FFT size may be equal to 128,256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20megahertz (MHz), respectively. The system bandwidth may also bepartitioned into subbands. For example, a subband may cover 1.08 MHz(i.e., 6 resource blocks), and there may be 1, 2, 4, 8 or 16 subbandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using time division duplex (TDD). A singlecomponent carrier bandwidth of 100 MHz may be supported. NR resourceblocks may span 12 sub-carriers with a sub-carrier bandwidth of 75 kHzover a 0.1 ms duration. Each radio frame may consist of 50 subframeswith a length of 10 ms. Consequently, each subframe may have a length of0.2 ms. Each subframe may indicate a link direction (i.e., DL or UL) fordata transmission and the link direction for each subframe may bedynamically switched. Each subframe may include DL/UL data as well asDL/UL control data. UL and DL subframes for NR may be as described inmore detail below with respect to FIGS. 6 and 7 . Beamforming may besupported and beam direction may be dynamically configured. MIMOtransmissions with precoding may also be supported. MIMO configurationsin the DL may support up to 8 transmit antennas with multi-layer DLtransmissions up to 8 streams and up to 2 streams per UE. Multi-layertransmissions with up to 2 streams per UE may be supported. Aggregationof multiple cells may be supported with up to 8 serving cells.Alternatively, NR may support a different air interface, other than anOFDM-based. NR networks may include entities such CUs and/or DUs.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the only entities that may function as a scheduling entity. That is,in some examples, a UE may function as a scheduling entity, schedulingresources for one or more subordinate entities (e.g., one or more otherUEs). In this example, the UE is functioning as a scheduling entity, andother UEs utilize resources scheduled by the UE for wirelesscommunication. A UE may function as a scheduling entity in apeer-to-peer (P2P) network, and/or in a mesh network. In a mesh networkexample, UEs may optionally communicate directly with one another inaddition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As noted above, a RAN may include a CU and DUs. A NR BS (e.g., eNB, 5GNode B, Node B, transmission reception point (TRP), access point (AP))may correspond to one or multiple BSs. NR cells can be configured asaccess cell (ACells) or data only cells (DCells). For example, the RAN(e.g., a central unit or distributed unit) can configure the cells.DCells may be cells used for carrier aggregation or dual connectivity,but not used for initial access, cell selection/reselection, orhandover. In some cases DCells may not transmit synchronizationsignals—in some case cases DCells may transmit SS. NR BSs may transmitdownlink signals to UEs indicating the cell type. Based on the cell typeindication, the UE may communicate with the NR BS. For example, the UEmay determine NR BSs to consider for cell selection, access, handover,and/or measurement based on the indicated cell type.

FIG. 2 illustrates an example logical architecture of a distributedradio access network (RAN) 200, which may be implemented in the wirelesscommunication system illustrated in FIG. 1 . A 5G access node 206 mayinclude an access node controller (ANC) 202. The ANC may be a centralunit (CU) of the distributed RAN 200. The backhaul interface to the nextgeneration core network (NG-CN) 204 may terminate at the ANC. Thebackhaul interface to neighboring next generation access nodes (NG-ANs)may terminate at the ANC. The ANC may include one or more TRPs 208(which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs, orsome other term). As described above, a TRP may be used interchangeablywith “cell.”

The TRPs 208 may be a DU. The TRPs may be connected to one ANC (ANC 202)or more than one ANC (not illustrated). For example, for RAN sharing,radio as a service (RaaS), and service specific AND deployments, the TRPmay be connected to more than one ANC. A TRP may include one or moreantenna ports. The TRPs may be configured to individually (e.g., dynamicselection) or jointly (e.g., joint transmission) serve traffic to a UE.

The local architecture 200 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based on transmit network capabilities (e.g.,bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 210 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 208. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 202. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture 200. As will be described in moredetail with reference to FIG. 5 , the Radio Resource Control (RRC)layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control(RLC) layer, Medium Access Control (MAC) layer, and a Physical (PHY)layers may be adaptably placed at the DU or CU (e.g., TRP or ANC,respectively). According to certain aspects, a BS may include a centralunit (CU) (e.g., ANC 202) and/or one or more distributed units (e.g.,one or more TRPs 208).

FIG. 3 illustrates an example physical architecture of a distributed RAN300, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 302 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 304 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A DU 306 may host one or more TRPs (edge node (EN), an edge unit (EU), aradio head (RH), a smart radio head (SRH), or the like). The DU may belocated at edges of the network with radio frequency (RF) functionality.

FIG. 4 illustrates example components of the BS 110 and UE 120illustrated in FIG. 1 , which may be used to implement aspects of thepresent disclosure. As described above, the BS may include a TRP. One ormore components of the BS 110 and UE 120 may be used to practice aspectsof the present disclosure. For example, antennas 452, Tx/Rx 222,processors 466, 458, 464, and/or controller/processor 480 of the UE 120and/or antennas 434, processors 460, 420, 438, and/orcontroller/processor 440 of the BS 110 may be used to perform theoperations described herein.

FIG. 4 shows a block diagram of a design of a BS 110 and a UE 120, whichmay be one of the BSs and one of the UEs in FIG. 1 . For a restrictedassociation scenario, the base station 110 may be the macro BS 110 c inFIG. 1 , and the UE 120 may be the UE 120 y. The base station 110 mayalso be a base station of some other type. The base station 110 may beequipped with antennas 434 a through 434 t, and the UE 120 may beequipped with antennas 452 a through 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the Physical Broadcast Channel(PBCH), Physical Control Format Indicator Channel (PCFICH), PhysicalHybrid ARQ Indicator Channel (PHICH), Physical Downlink Control Channel(PDCCH), etc. The data may be for the Physical Downlink Shared Channel(PDSCH), etc. The processor 420 may process (e.g., encode and symbolmap) the data and control information to obtain data symbols and controlsymbols, respectively. The processor 420 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 430 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 432 a through 432t. For example, the TX MIMO processor 430 may perform certain aspectsdescribed herein for RS multiplexing. Each modulator 432 may process arespective output symbol stream (e.g., for OFDM, etc.) to obtain anoutput sample stream. Each modulator 432 may further process (e.g.,convert to analog, amplify, filter, and upconvert) the output samplestream to obtain a downlink signal. Downlink signals from modulators 432a through 432 t may be transmitted via the antennas 434 a through 434 t,respectively.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. For example, MIMO detector 456 may provide detected RStransmitted using techniques described herein. A receive processor 458may process (e.g., demodulate, deinterleave, and decode) the detectedsymbols, provide decoded data for the UE 120 to a data sink 460, andprovide decoded control information to a controller/processor 480.According to one or more cases, CoMP aspects can include providing theantennas, as well as some Tx/Rx functionalities, such that they residein distributed units. For example, some Tx/Rx processing can be done inthe central unit, while other processing can be done at the distributedunits. For example, in accordance with one or more aspects as shown inthe diagram, the BS mod/demod 432 may be in the distributed units.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the Physical Uplink Shared Channel (PUSCH)) froma data source 462 and control information (e.g., for the Physical UplinkControl Channel (PUCCH) from the controller/processor 480. The transmitprocessor 464 may also generate reference symbols for a referencesignal. The symbols from the transmit processor 464 may be precoded by aTX MIMO processor 466 if applicable, further processed by thedemodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. At the BS 110, the uplink signalsfrom the UE 120 may be received by the antennas 434, processed by themodulators 432, detected by a MIMO detector 436 if applicable, andfurther processed by a receive processor 438 to obtain decoded data andcontrol information sent by the UE 120. The receive processor 438 mayprovide the decoded data to a data sink 439 and the decoded controlinformation to the controller/processor 440.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect, e.g., the execution of the functional blocks illustrated in FIG.9 , and/or other processes for the techniques described herein. Theprocessor 480 and/or other processors and modules at the UE 120 may alsoperform or direct, e.g., the execution of the functional blocksillustrated in FIG. 10 , and/or other processes for the techniquesdescribed herein. The memories 442 and 482 may store data and programcodes for the BS 110 and the UE 120, respectively. A scheduler 444 mayschedule UEs for data transmission on the downlink and/or uplink.

FIG. 5 illustrates a diagram 500 showing examples for implementing acommunications protocol stack, according to aspects of the presentdisclosure. The illustrated communications protocol stacks may beimplemented by devices operating in a in a 5G system (e.g., a systemthat supports uplink-based mobility). Diagram 500 illustrates acommunications protocol stack including a Radio Resource Control (RRC)layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a RadioLink Control (RLC) layer 520, a Medium Access Control (MAC) layer 525,and a Physical (PHY) layer 530. In various examples the layers of aprotocol stack may be implemented as separate modules of software,portions of a processor or ASIC, portions of non-collocated devicesconnected by a communications link, or various combinations thereof.Collocated and non-collocated implementations may be used, for example,in a protocol stack for a network access device (e.g., ANs, CUs, and/orDUs) or a UE.

A first option 505-a shows a split implementation of a protocol stack,in which implementation of the protocol stack is split between acentralized network access device (e.g., an ANC 202 in FIG. 2 ) anddistributed network access device (e.g., DU 208 in FIG. 2 ). In thefirst option 505-a, an RRC layer 510 and a PDCP layer 515 may beimplemented by the central unit, and an RLC layer 520, a MAC layer 525,and a PHY layer 530 may be implemented by the DU. In various examplesthe CU and the DU may be collocated or non-collocated. The first option505-a may be useful in a macro cell, micro cell, or pico celldeployment.

A second option 505-b shows a unified implementation of a protocolstack, in which the protocol stack is implemented in a single networkaccess device (e.g., access node (AN), new radio base station (NR BS), anew radio Node-B (NR NB), a network node (NN), or the like.). In thesecond option, the RRC layer 510, the PDCP layer 515, the RLC layer 520,the MAC layer 525, and the PHY layer 530 may each be implemented by theAN. The second option 505-b may be useful in a femto cell deployment.

Regardless of whether a network access device implements part or all ofa protocol stack, a UE may implement an entire protocol stack (e.g., theRRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525,and the PHY layer 530).

FIG. 6 is a diagram 600 showing an example of a DL-centric subframe. TheDL-centric subframe may include a control portion 602. The controlportion 602 may exist in the initial or beginning portion of theDL-centric subframe. The control portion 602 may include variousscheduling information and/or control information corresponding tovarious portions of the DL-centric subframe. In some configurations, thecontrol portion 602 may be a physical DL control channel (PDCCH), asindicated in FIG. 6 . The DL-centric subframe may also include a DL dataportion 604. The DL data portion 604 may sometimes be referred to as thepayload of the DL-centric subframe. The DL data portion 604 may includethe communication resources utilized to communicate DL data from thescheduling entity (e.g., UE or BS) to the subordinate entity (e.g., UE).In some configurations, the DL data portion 604 may be a physical DLshared channel (PDSCH).

The DL-centric subframe may also include a common UL portion 606. Thecommon UL portion 606 may sometimes be referred to as an UL burst, acommon UL burst, and/or various other suitable terms. The common ULportion 606 may include feedback information corresponding to variousother portions of the DL-centric subframe. For example, the common ULportion 606 may include feedback information corresponding to thecontrol portion 602. Non-limiting examples of feedback information mayinclude an ACK signal, a NACK signal, a HARQ indicator, and/or variousother suitable types of information. The common UL portion 606 mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests (SRs), and various other suitable types of information. Asillustrated in FIG. 6 , the end of the DL data portion 604 may beseparated in time from the beginning of the common UL portion 606. Thistime separation may sometimes be referred to as a gap, a guard period, aguard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the subordinate entity (e.g., UE)) to UL communication(e.g., transmission by the subordinate entity (e.g., UE)). One ofordinary skill in the art will understand that the foregoing is merelyone example of a DL-centric subframe and alternative structures havingsimilar features may exist without necessarily deviating from theaspects described herein.

FIG. 7 is a diagram 700 showing an example of an UL-centric subframe.The UL-centric subframe may include a control portion 702. The controlportion 702 may exist in the initial or beginning portion of theUL-centric subframe. The control portion 702 in FIG. 7 may be similar tothe control portion described above with reference to FIG. 6 . TheUL-centric subframe may also include an UL data portion 704. The UL dataportion 704 may sometimes be referred to as the payload of theUL-centric subframe. The UL data portion may refer to the communicationresources utilized to communicate UL data from the subordinate entity(e.g., UE) to the scheduling entity (e.g., UE or BS). In someconfigurations, the control portion 702 may be a physical DL controlchannel (PDCCH).

As illustrated in FIG. 7 , the end of the control portion 702 may beseparated in time from the beginning of the UL data portion 704. Thistime separation may sometimes be referred to as a gap, guard period,guard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the scheduling entity) to UL communication (e.g.,transmission by the scheduling entity). The UL-centric subframe may alsoinclude a common UL portion 706. The common UL portion 706 in FIG. 7 maybe similar to the common UL portion 706 described above with referenceto FIG. 7 . The common UL portion 706 may additionally or alternativelyinclude information pertaining to channel quality indicator (CQI),sounding reference signals (SRSs), and various other suitable types ofinformation. One of ordinary skill in the art will understand that theforegoing is merely one example of an UL-centric subframe andalternative structures having similar features may exist withoutnecessarily deviating from the aspects described herein.

In some circumstances, two or more subordinate entities (e.g., UEs) maycommunicate with each other using sidelink signals. Real-worldapplications of such sidelink communications may include public safety,proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V)communications, Internet of Everything (IoE) communications, IoTcommunications, mission-critical mesh, and/or various other suitableapplications. Generally, a sidelink signal may refer to a signalcommunicated from one subordinate entity (e.g., UE1) to anothersubordinate entity (e.g., UE2) without relaying that communicationthrough the scheduling entity (e.g., UE or BS), even though thescheduling entity may be utilized for scheduling and/or controlpurposes. In some examples, the sidelink signals may be communicatedusing a licensed spectrum (unlike wireless local area networks, whichtypically use an unlicensed spectrum).

A UE may operate in various radio resource configurations, including aconfiguration associated with transmitting pilots using a dedicated setof resources (e.g., a radio resource control (RRC) dedicated state,etc.) or a configuration associated with transmitting pilots using acommon set of resources (e.g., an RRC common state, etc.). Whenoperating in the RRC dedicated state, the UE may select a dedicated setof resources for transmitting a pilot signal to a network. Whenoperating in the RRC common state, the UE may select a common set ofresources for transmitting a pilot signal to the network. In eithercase, a pilot signal transmitted by the UE may be received by one ormore network access devices, such as an AN, or a DU, or portionsthereof. Each receiving network access device may be configured toreceive and measure pilot signals transmitted on the common set ofresources, and also receive and measure pilot signals transmitted ondedicated sets of resources allocated to the UEs for which the networkaccess device is a member of a monitoring set of network access devicesfor the UE. One or more of the receiving network access devices, or a CUto which receiving network access device(s) transmit the measurements ofthe pilot signals, may use the measurements to identify serving cellsfor the UEs, or to initiate a change of serving cell for one or more ofthe UEs.

Example Slot Design

In mobile communication systems conforming to certain wirelesscommunications standards, such as the Long Term Evolution (LTE)standards, certain techniques may be used to increase the reliability ofdata transmission. For example, after a base station performs an initialtransmission operation for a specific data channel, a receiver receivingthe transmission attempts to demodulate the data channel during whichthe receiver performs a cyclic redundancy check (CRC) for the datachannel. If, as a result of the check, the initial transmission issuccessfully demodulated, the receiver may send an acknowledgement (ACK)to the base station to acknowledge the successful demodulation. If,however, the initial transmission is not successfully demodulated, thereceiver may send a non-acknowledgement (NACK) to the base station. Achannel that transmits ACK/NACK is called a response or an ACK channel.

In some cases, under the LTE standards, an ACK channel may comprise twoslots (i.e. one subframe) or 14 symbols, which may be used to transmitan ACK that may comprise one or two bits of information. In some cases,when transmitting ACK channel information, a wireless device may performfrequency hopping. Frequency hopping refers to the practice ofrepeatedly switching frequencies within a frequency band in order toreduce interference and avoid interception.

Under other wireless communications standards, such as NR, the ACKchannel information as well as other information may be transmittedthrough an uplink structure shown in FIG. 8 a . FIG. 8 a illustrates anexample uplink structure with a transmission time interval (TTI) thatincludes a region for long uplink burst transmissions. The long uplinkburst may transmit information such as acknowledgment (ACK), channelquality indicator (CQI), or scheduling request (SR) information.

The duration of the region for long uplink burst transmissions, referredto in FIG. 8 as “UL Long Burst,” may vary depending on how many symbolsare used for the physical downlink control channel (PDCCH), the gap, andthe short uplink burst (shown as UL Short Burst), as shown in FIG. 8 .For example, the UL Long Burst may comprise a number of slots (e.g., 4),where the duration of each slot may vary from 4 to 14 symbols. FIG. 8 balso shows a downlink structure having a TTI that includes PDCCH,downlink physical downlink shared channel (PDSCH), a gap, and an uplinkshort burst. Similar to the UL Long Burst, the duration of the DL PDSCHmay also depend on the number of symbols used by the PDCCH, the gap, andthe uplink short burst.

As noted above, UL short burst may be 1 or 2 symbols and differentapproaches may be used to transmit UCI in this duration. For example,according to a “1 symbol” UCI design, 3 or more bits of UCI may be sentusing frequency division multiplexing (FDM). For 1 or 2 bits ofacknowledgment (ACK) or a 1 bit scheduling request (SR), a sequencebased design may be used. For example, an SR may be sent with 1sequence, on-off keying, and may multiplex up to 12 users per RB. For a1-bit ACK, 2 sequences may be used, and up to 6 users may be multiplexedper RB. For a 2-bit ACK, 4 sequences may be used and up to 3 users maybe multiplexed per RB.

Example RE Mapping Rule For UCI Piggyback on PUSCH

There are a number of approaches to multiplex simultaneous PUCCH andPUSCH from a same UE that may be provided. For example, a first approachmay include transmitting PUCCH and PUSCH on different RBs, such as, FDMPUCCH and PUSCH. A second approach may include piggybacking PUCCH onassigned PUSCH RBs. Both approaches may be supported in NR.

UCI piggybacking on PUSCH may include, for frequency first mapping, UCIresource mapping principles (e.g., around RS) that may be common forPUSCH with DFT-s-OFDM waveform and CP-OFDM waveform. UCI piggybacking onPUSCH may also include UL data that may be rate-matched around the UCIat least for a periodic CSI report configured by RRC and/or an aperiodicCSI report triggered by UL grant.

In one or more cases, slot-based scheduling for HARQ-ACK with more thantwo bits may include PUSCH that is rate-matched. In some cases, PUSCHmay be punctured for slot-based scheduling for HARQ-ACK with up to twobits. In one or more cases, NR may provide a sufficiently reliablecommon understanding on HARQ-ACK bits between gNB and UE. In some cases,additional considerations may be taken into account regarding channelmultiplexing of PUCCH and PUSCH.

Considerations associated with UCI piggybacking on PUSCH may include howto decide the HARQ-ACK piggyback rule. For example, if PUSCH ispunctured by ACK, in the case of a large ACK payload size, the impact toPUSCH decoding performance may be non-negligible. If PUSCH israte-matched around ACK, in cases where a UE miss-detects DCI, an eNBand UE may have different assumption on the number of ACK bitspiggybacked on PUSCH, which may require the eNB to performance blinddetection to solve such an ambiguity. Further, as the ACK payload sizeincreases, a number of blind detections that the eNB may need to performmay also increase.

Example PUCCH Resource Allocation For NR

Aspects of the present disclosure relate to methods and apparatus fordetermining resources allocated for transmitting uplink controlinformation in a physical uplink control channel (PUCCH).

In some cases, to signal resources available for sending uplink controlinformation (UCI) such as ACK/NACK or SR, an eNB may use allocationresource indicator (ARI) bits. The ARI bits may explicitly indicatePUCCH resources available for transmitting UCI. For example, a 2-bit ARImay indicate one of four resources available for transmitting UCI.

In some cases, there may be more sets of resources available than can beexplicitly signaled. For example, if there are more than four sets ofresources, a 2-bit ARI may be insufficient and an implicit mapping forPUCCH resource allocation may be used. The number of PUCCH resources ina resource set is configured.

As will be described herein, aspects of the present disclosure providetechniques for implicitly signaling a sub-set within a resource set,where no additional RRC impact is necessary. For example, additional RRCsignaling may not be needed for the implicit signaling, thereby reduingnetwork bandwidth for indicating resources available for transmittingUCI.

FIG. 9 illustrates example operations 900 that may be performed by anetwork entity, such as an eNB, for allocating PUCCH resources inaccordance with aspects of the present disclosure.

Operations 900 begin, at 902, by transmitting downlink controlinformation (DCI) comprising one or more resource indicator (RI) bitsconfigured to indicate a subset of resources, from a plurality ofsubsets, available for a user equipment (UE) to use for a transmittinguplink control information (UCI) in a physical uplink control channel(PUCCH) transmission. At 904, the network entity identifies resources,within the subset indicated by the RI bits, to monitor for the PUCCHtransmission based on an implicit mapping. At 906, the network entitymonitors the identified resources for the PUCCH transmission.

FIG. 10 illustrates example operations 1000 that may be performed by auser equipment (UE), in accordance with aspects of the presentdisclosure. For example, operations 1000 may be performed by a UE todetermine resources for sending to an eNB performing operations 900.

Operations 1000 begin, at 1002, by receiving downlink controlinformation (DCI) comprising one or more resource indicator (RI) bitsconfigured to indicate a subset of resources available for transmittinguplink control information (UCI) in a physical uplink control channel(PUCCH) transmission. At 1004, the UE identifies resources within thesubset indicated by the RI bits to transmit the UCI based on an implicitmapping. At 1006, the UE transmits the UCI using the identifiedresources.

FIG. 11 illustrates an example of resource allocation for a physicaluplink control channel (PUCCH) transmission, in accordance with certainaspects of the present disclosure. For example, FIG. 11 shows howdifferent sets of resources (e.g., time resources, frequency resources,etc.) may be available for PUCCH transmission. Different UEs may beconfigured with different sets, via RRC signaling. In some cases,explicit signaling (e.g., ARI bits) may be used to signal one of thesets of resources, while implicit mapping may be used to identifyresources within the sets.

For example, FIG. 11 illustrates a set of PUCCH resources 1102configured for a first UE 120 a and a set of PUCCH resources 1104configured for a second UE 120 b. As shown, the set of PUCCH resources1102 are divided into subsets of resources 1112. In particular, incertain aspects as shown, the set of PUCCH resources 1102 are dividedinto 8 subsets of resources 1112. The subsets of resources 1112 arefurther divided into the PUCCH resources 1122. Similarly, the set ofPUCCH resources 1104 are divided into subsets of resources 1114. Inparticular, in certain aspects as shown, the set of PUCCH resources 1104are divided into 8 subsets of resources 1114. The subsets of resources1114 are further divided into the PUCCH resources 1124. In certainaspects, the sets of PUCCH resources 1102 and 1104 may be divided into adifferent number of subsets of resources 1112 and 1114.

As shown in FIG. 11 , each subset of resources 1112 includes 4 resourcesper subset, while each subset of resources 1114 includes 2 resources persubset. In certain aspects, the subsets of resources 1112 and subsets ofresources 1114 include different numbers of PUCCH resources than shown.The size of a subset of resources 1112/1114 may correspond to the numberof PUCCH resources in the subset. In certain aspects, each subset ofresources for a given UE (e.g., subsets 1112 or subsets 1114) has thesame size. In certain aspects, at least two different subsets of a givenUE have a different size. In certain aspects, at least two different UEshave subsets of different sizes. In certain aspects, UEs have subsets ofthe same size.

FIG. 11 further illustrates a set of PDCCH resources 1106 including aplurality of PDCCH resources 1126. As shown, the PDCCH resources 1126may map to PUCCH resources 1122/1124. In particular, in certainembodiments, the PDCCH resources 1126 used for transmission by BS 110 toUEs 120 on the DL are mapped to PUCCH resources used for transmission byUEs 120 to BS 110 on the UL. In certain aspects, the BS 110 maydetermine what to include in the PDCCH resources 1126 to indicateinformation to the UEs 120 as to what PUCCH resources to use andtransmit such information in the PDCCH resources 1126. Further, incertain aspects, a given UE 120 may determine which PUCCH resources touse for transmission based on which PDCCH resources 1126 the UE 120receives transmissions, and information in the transmissions.

In certain aspects, the BS 110 explicitly signaling in the PDCCH to theUE 120 exactly which resources (e.g., time resources, frequencyresources, etc.) of the PUCCH to use for transmitting UCI (e.g., atransmission such as transport block (TB), etc.) may require a largenumber of bits, which may be inefficient. For example, the set of PUCCHresources 1102 may include 32 PUCCH resources 1122, requiring 5-bits tosignal. Accordingly, explicitly signaling in the PDCCH the resources onthe PUCCH to use for transmitting UCI may utilize network bandwidth forthe signaling, and therefore increase network overhead in the network,thereby reducing overall data throughput. Accordingly, certain aspectsherein relate to at least partially implicitly mapping the resources inthe PDCCH to UL resources on the PUCCH to utilize for communicating theUCI on the PUCCH. Both a UE and BS may perform the implicit mapping, theUE to determine which PUCCH resources to use to transmit the UCI andactually transmit the UCI, and the BS to receive the UCI and determinewhich data transmission the UCI is for based on the PUCCH resources onwhich it is received.

In certain aspects, BS 110 may transmit DCI with one or more RI bits toindicate a subset of resources available for transmitting UCI in a PUCCHtransmission. The RI bits may accordingly be used to explicitly map to aparticular subset of resources 1112/1114 of a set of PUCCH resources1102/1104 associated with the UE 120 the DCI is sent to (i.e., intendedfor).

The PDCCH may span a number of subcarriers in the frequency domain and anumber of OFDM symbols in the time domain. The minimum resource elementof a PDCCH may be referred to as a resource element (RE) and correspondto one OFDM symbol and one subcarrier. REs may be grouped into resourceelement groups (REGs). Each REG may include a number of (e.g., 4consecutive) REs within the same OFDM symbol and the same resource block(RB). REGs may be grouped into control channel elements (CCEs). Each CCEmay include a number of (e.g., 9 contiguous) REGs. The CCEs in the PDCCHmay be indexed and each CCE referenced by index number corresponding tothe position of the CCE in the PDCCH. Accordingly, the DCI transmissionby the BS 110 may be carried in a particular CCE of a PDCCH, the CCEhaving a particular index.

In certain aspects, the CCE index of the CCE carrying the DCI may beused to implicitly map to a particular PUCCH resource 1122/1124 in thesubset of resources 1112/1114 indicated by the DCI.

In certain aspects, if there are X number of RI bits signaled to the UE120 by the BS 110 (e.g., in DCI of a PDCCH), and there are Y number ofPUCCH resources (e.g., 1122 or 1124) the UE 120 is configured (e.g.,using RRC) to use for one set of PUCCH resources (e.g., 1102 or 1104),then there may be 2{circumflex over ( )}X subsets of resources (e.g.,1112 or 1114) indicated by the RI bits. If Y/(2{circumflex over ( )}X)is not an integer, then different subsets may have a different size.

In certain aspects, if Z=Y % 2{circumflex over ( )}X andM=floor(Y/2{circumflex over ( )}X), then there may be 2{circumflex over( )}X−Z subsets with M PUCCH resources, and Z subsets with M+1 PUCCHresources.

In certain aspects, the Y resources may be divided into 2{circumflexover ( )}X subsets of resources as follows: 1) for the first Z subsetseach has M+1 resources; and 2) the remaining subsets each have Mresources. In certain other aspects, the Y resources may be divided into2{circumflex over ( )}X subsets of resources as follows: 1) the first2{circumflex over ( )}X−Z subsets each have M PUCCH resources; and 2)the remaining subsets each have M+1 PUCCH resources.

In certain aspects, a base station (e.g., BS 110) and UE 120 may supportcarrier aggregation (CA), meaning the BS 110 and UE 120 can communicateover multiple frequencies (e.g., multiple ranges of frequencies of oneor more bandwidths) referred to as carriers, or component carriers(CCs). These carriers may or may not be contiguous in frequency. When CAis used by the BS 110, the BS 110 may support a plurality of servingcells, one for each carrier. The coverage area of each serving cell maydiffer. In certain aspects, radio resource control (RRC) connectionprocedures (e.g., during handover, after a radio link failure (RLF), forinitial connection, etc.) for the UE 120 connecting to the BS 110 arehandled by the BS 110 using only one of the carriers (referred to as aprimary carrier), which serves one of the cells referred to as theprimary cell (PCell). The remaining cells may be referred to assecondary cells (SCells) and are served by the remaining carriers(referred to as secondary carriers).

In certain aspects, PDCCH is carried on multiple CCs (e.g., each CC).Accordingly, if there are multiple CCs used for communication betweenthe BS 110 and a UE 120, there may be multiple PDCCHs transmitted onmultiple CCs (e.g., a PDCCH on each CC) from BS 110 to UE 120. Incertain aspects, only one of the multiple PDCCHs may be used to map toPUCCH resources. In certain aspects, the other PDCCHs are ignored (e.g.,any RI bits and CCE index of the CCE carrying the RI bits in the otherPDCCHs are ignored and not used to map to PUCCH resources). In certainaspects, the PDCCH carried on the CC with the smallest/lowest index isused to map to PUCCH resources using the techniques described herein. Incertain aspects, the PDCCH carried on the CC with the largest/highestindex is used to map to PUCCH resources using the techniques describedherein. In certain aspects, the UCI for the multiple PDCCH aretransmitted in the same UL slot.

Similarly, to how multiple PDCCHs may be transmitted from BS 110 to UE120 using multiple CCs, multiple PDCCHs may be transmitted from BS 110to UE 120 on multiple slots (e.g., time slots when using cross slotscheduling). Accordingly, there may be multiple ACK bits transmitted onthe same UL slot. In certain aspects, only one of the multiple PDCCHsmay be used to map to PUCCH resources. In certain aspects, the otherPDCCHs are ignored (e.g., any RI bits and CCE index of the CCE carryingthe RI bits in the other PDCCHs are ignored and not used to map to PUCCHresources). In certain aspects, the PDCCH received at the UE 120 (e.g.,transmitted by the BS 110) in the most recent/last slot in time is usedto map to PUCCH resources using the techniques described herein. Incertain aspects, the UCI for the multiple PDCCH are transmitted in thesame UL slot.

In certain aspects, UE 120 may be configured to transmit a schedulingrequest (SR) to BS 110 to send an UL grant to the UE 120 for the UE 120to transmit (e.g., on PUSCH). In certain aspects, the SR may have aperiodicity that is small (e.g., less than slot duration, such as 1, 2,or 3 symbols). Accordingly, a positive SR may show up (e.g., need to betransmitted by the UE 120) in the middle of or during a long PUCCH orPUSCH transmission from the UE 120. In certain such aspects, such a SRis for an ultra-reliable low latency communications (URLLC) UE 120. Incertain such aspects, such a SR is for an enhanced mobile broadband(eMBB) UE 120. In certain such aspects, such a SR is for a UE thatsupports eMBB and URLLC.

In certain aspects, if there is a long PUCCH (e.g., for URLLC oreMMB)/PUSCH transmitted by the UE 120 and a SR shows up, the UE 120 maydrop the long PUCCH/PUSCH from that SR symbol. For example, the UE 120may transmit PUCCH/PUSCH in symbols up until the SR symbol, and then nottransmit PUCCH/PUSCH on the remaining symbols.

In certain aspects, if a SR symbol (e.g., for URLLC) shows up duringPUSCH or PUCCH transmission (e.g., for eMMB) at a given UE 120, the UE120 may drop the long PUCCH/PUSCH from that SR symbol to yield to URLLC.

In certain aspects, when UE 120 transmits ACK (e.g., or UCI) on PUSCH,for 1 or 2 bits of ACK, the ACK bits puncture PUSCH. For ACK>2 bits, ACKbits are rate matched around by the PUSCH.

In order to avoid confusion on the number of ACK bits between the UE 120and BS 110, e.g., to successfully decode the ACK bits and data on PUSCH,the BS 110 may include in the UL grant to the UE 120 downlink assignmentindex (DAI) bits (e.g., 2 or 3) to indicate the number of ACK bits theUE 120 should transmit on PUSCH.

In certain aspects, the UE 120 and BS 110 are configured with asemi-static HARQ-ACK codebook size (e.g., when transmitting ACK alwaystransmit X (e.g., 4) number of bits). For example, the HARQ-ACK payloadsize is given in RRC signaling from BS 110 to UE 120. Therefore, theonly uncertainty is if there are any ACK bits at all. For example, theUE 120 may not successfully receive PDCCH/PDSCH, then it may not know itneeds to transmit ACK bits. Accordingly, in certain aspects, when usinga semi-static HARQ-ACK codebook size, 1 DAI bit may be added to the ULgrant to indicate if ACK bits are expected or not.

In certain aspects, no DAI bits are added to the UL grant, andaccordingly, the BS 110 may need to do blind detection on the twohypothesis (either PUSCH only (0, 1, 2 ACK bits) or PUSCH rate matchedaround X ACK bits). The correct hypothesis is then used by the BS 110 toget the data and ACK bits (if present).

FIG. 12 illustrates a communications device 1200 that may includevarious components (e.g., corresponding to means-plus-functioncomponents) configured to perform operations for the techniquesdisclosed herein, such as the operations illustrated in FIG. 9 or 10 .The communications device 1200 includes a processing system 1202 coupledto a transceiver 1208. The transceiver 1208 is configured to transmitand receive signals for the communications device 1200 via an antenna1210, such as the various signal described herein. The processing system1202 may be configured to perform processing functions for thecommunications device 1200, including processing signals received and/orto be transmitted by the communications device 1200.

The processing system 1202 includes a processor 1204 coupled to acomputer-readable medium/memory 1212 via a bus 1206. In certain aspects,the computer-readable medium/memory 1212 is configured to storeinstructions that when executed by processor 1204, cause the processor1204 to perform the operations illustrated in FIG. 9 or 10 , or otheroperations for performing the various techniques discussed herein.

In certain aspects, the processing system 1202 further includes atransmitting component 1214 for performing the operations illustrated in902 of FIG. 9 or 1006 of FIG. 10 . Additionally, the processing system1202 includes an identifying component 1216 for performing theoperations illustrated in 904 of FIG. 9 or 1004 of FIG. 10 .Additionally, the processing system 1202 includes a monitoring component1218 for performing the operations illustrated in 906 of FIG. 9 .Additionally, the processing system 1202 includes a receiving component1220 for performing the operations illustrated in 1002 of FIG. 10 . Thetransmitting component 1214, identifying component 1216, monitoringcomponent 1218, and receiving component 1220 may be coupled to theprocessor 1204 via bus 1206. In certain aspects, the transmittingcomponent 1214, identifying component 1216, monitoring component 1218,and receiving component 1220 may be hardware circuits. In certainaspects, the transmitting component 1214, identifying component 1216,monitoring component 1218, and receiving component 1220 may be softwarecomponents that are executed and run on processor 1204.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or, in the case of a method claim, theelement is recited using the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

For example, means for transmitting and/or means for receiving maycomprise one or more of a transmit processor 420, a TX MIMO processor430, a receive processor 438, or antenna(s) 434 of the base station 110and/or the transmit processor 464, a TX MIMO processor 466, a receiveprocessor 458, or antenna(s) 452 of the user equipment 120.Additionally, means for generating, means for multiplexing, and/or meansfor applying may comprise one or more processors, such as thecontroller/processor 440 of the base station 110 and/or thecontroller/processor 480 of the user equipment 120.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1 ), a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method for wireless communications by a userequipment, comprising: receiving downlink control information (DCI)comprising one or more resource indicator (RI) bits configured toindicate to the user equipment a subset of resources available fortransmitting uplink control information (UCI) in a physical uplinkcontrol channel (PUCCH) transmission, wherein: the DCI is received onone or more resources of a first physical downlink control channel(PDCCH) transmission, wherein the subset is one of a plurality ofsubsets, each of the plurality of subsets corresponding to a uniquesubset of PUCCH resources; and a number of RI bits is X, wherein a totalnumber of PUCCH resources is Y, wherein a total number of subsets of thePUCCH resources is 2ΛX, wherein (Y modulo 2ΛX) of the total number ofsubsets consist of (floor(Y/2ΛX)+1) PUCCH resources and any remaining ofthe total number of subsets consist of (floor(Y/2ΛX)) PUCCH resources;determining, based on the RI bits of the DCI, the subset of resourcesavailable for transmitting UCI in the PUCCH; identifying a particularPUCCH resource within the determined subset of resources to transmit theUCI based on an implicit mapping of PDCCH resources to PUCCH resourcesand the one or more resources of the first PDCCH transmission; andtransmitting the UCI using the particular PUCCH resource.
 2. The methodof claim 1, further comprising: receiving multiple PDCCH transmissionson multiple component carriers (CCs) or across multiple slots, whereinthe UCI acknowledges the multiple PDCCH transmissions.
 3. The method ofclaim 1, further comprising receiving multiple PDCCH transmissions,wherein the first PDCCH transmission is a last transmission of themultiple PDCCH transmissions.
 4. The method of claim 1, furthercomprising receiving multiple PDCCH transmissions, wherein the firstPDCCH transmission has a smallest component carrier (CC) index of themultiple PDCCH transmissions.
 5. The method of claim 1, furthercomprising receiving multiple PDCCH transmissions, wherein the UCIacknowledges the multiple PDCCH transmissions, and wherein the UCI issent in a same uplink (UL) slot.
 6. The method of claim 1, wherein atleast two of the plurality of subsets have different sizes.
 7. Themethod of claim 1, wherein each of the plurality of subsets has the samesize.
 8. The method of claim 1, wherein the implicit mapping is based ona control channel element (CCE) index of the first PDCCH transmission.9. A method for wireless communications by a user equipment, comprising:receiving, from a base station, an uplink grant comprising an indicationof an uplink resource to transmit an acknowledgement (ACK) and one ormore downlink assignment index (DAI) bits; determining a number of bitsto use to transmit the ACK based on the DAI bits; and transmitting, tothe base station, the ACK via the uplink resource using the determinednumber of bits, wherein when the user equipment and base station areconfigured with a semi-static HARQ-ACK codebook size, a number of DAIbits is one and the one DAI bit is added to the uplink grant to indicateto the user equipment whether or not to transmit the ACK and the numberof bits are determined according to the semi-static HARQ-ACK codebooksize.
 10. The method of claim 9, wherein transmitting the ACK via theuplink resource comprises transmitting the ACK on a physical uplinkshared channel (PUSCH).
 11. The method of claim 10, wherein when thedetermined number of bits is 1 or 2 the ACK punctures the PUSCH, andwherein when the determined number of bits is greater than 2 the ACK israte matched around the PUSCH.
 12. A method for wireless communicationsby a network entity, comprising: transmitting downlink controlinformation (DCI) comprising one or more resource indicator (RI) bitsconfigured to indicate to a user equipment a subset of resourcesavailable for transmitting uplink control information (UCI) in aphysical uplink control channel (PUCCH) transmission, wherein: the DCIis received on one or more resources of a first physical downlinkcontrol channel (PDCCH) transmission, wherein the subset is one of aplurality of subsets, each of the plurality of subsets corresponding toa unique subset of PUCCH resources; and a number of RI bits is X,wherein a total number of PUCCH resources is Y, wherein a total numberof subsets of the PUCCH resources is 2^(∧)X, wherein (Y modulo 2^(∧)X)of the total number of subsets consist of (floor(Y/2^(∧)X)+1) PUCCHresources and any remaining of the total number of subsets consist of(floor(Y/2^(∧)X)) PUCCH resources; determining, based on the RI bits ofthe DCI, the subset of resources available for transmitting UCI in thePUCCH; identifying a particular PUCCH resource within the determinedsubset of resources to monitor for the UCI based on an implicit mappingof PDCCH resources to PUCCH resources and the one or more resources ofthe first PDCCH transmission; and monitoring the particular PUCCHresource for the UCI.
 13. The method of claim 12, further comprising:transmitting multiple PDCCH transmissions on multiple component carriers(CCs) or across multiple slots, wherein the UCI acknowledges themultiple PDCCH transmissions.
 14. The method of claim 12, furthercomprising transmitting multiple PDCCH transmissions, wherein the firstPDCCH transmission is a last transmission of the multiple PDCCHtransmissions.
 15. The method of claim 12, further comprisingtransmitting multiple PDCCH transmissions, wherein the first PDCCHtransmission has a smallest component carrier (CC) index of the multiplePDCCH transmissions.
 16. The method of claim 12, further comprisingtransmitting multiple PDCCH transmissions, wherein the UCI acknowledgesthe multiple PDCCH transmissions, and wherein the UCI is communicated ina same uplink (UL) slot.
 17. The method of claim 12, wherein at leasttwo of the plurality of subsets have different sizes.
 18. The method ofclaim 12, wherein each of the plurality of subsets has the same size.19. The method of claim 12, wherein the implicit mapping is based on acontrol channel element (CCE) index of the first PDCCH transmission. 20.A method for wireless communications by a network entity, comprising:transmitting, to a user equipment, an uplink grant comprising anindication of an uplink resource to transmit an acknowledgement (ACK)and one or more downlink assignment index (DAI) bits indicating a numberof bits for the user equipment to use to transmit the ACK; andreceiving, from the user equipment, the ACK via the uplink resourceusing the number of bits, wherein when the user equipment and thenetwork entity are configured with a semi-static HARQ-ACK codebook size,a number of DAI bits is one and the one DAI bit is added to the uplinkgrant to indicate to the user equipment whether or not to transmit theACK and the number of bits are determined according to the semi-staticHARQ-ACK codebook size.
 21. The method of claim 20, wherein receivingthe ACK via the uplink resource comprises receiving the ACK on aphysical uplink shared channel (PUSCH).
 22. The method of claim 21,wherein when the number of bits is 1 or 2 the ACK punctures the PUSCH,and wherein when the number of bits is greater than 2 the ACK is ratematched around the PUSCH.
 23. A user equipment comprising: a memory; anda processor coupled to the memory, wherein the processor is configuredto: receive downlink control information (DCI) comprising one or moreresource indicator (RI) bits configured to indicate to the userequipment a subset of resources available for transmitting uplinkcontrol information (UCI) in a physical uplink control channel (PUCCH)transmission, wherein: the DCI is received on one or more resources of afirst physical downlink control channel (PDCCH) transmission, whereinthe subset is one of a plurality of subsets, each of the plurality ofsubsets corresponding to a unique subset of PUCCH resources; and anumber of RI bits is X, wherein a total number of PUCCH resources is Y,wherein a total number of subsets of the PUCCH resources is 2^(∧)X,wherein (Y modulo 2^(∧)X) of the total number of subsets consist of(floor(Y/2^(∧)X)+1) PUCCH resources and any remaining of the totalnumber of subsets consist of (floor(Y/2^(∧)X)) PUCCH resources;determine, based on the RI bits of the DCI, the subset of resourcesavailable for transmitting UCI in the PUCCH; identify a particular PUCCHresource within the determined subset of resources to transmit the UCIbased on an implicit mapping of PDCCH resources to PUCCH resources andthe one or more resources of the first PDCCH transmission; and transmitthe UCI using the particular PUCCH resource.
 24. The user equipment ofclaim 23, wherein the processor is further configured to: receivemultiple PDCCH transmissions on multiple component carriers (CCs) oracross multiple slots, wherein the UCI acknowledges the multiple PDCCHtransmissions.
 25. The user equipment of claim 23, wherein the processoris further configured to receive multiple PDCCH transmissions, whereinthe first PDCCH transmission is a last transmission of the multiplePDCCH transmissions.
 26. The user equipment of claim 23, wherein theprocessor is further configured to receive multiple PDCCH transmissions,wherein the first PDCCH transmission has a smallest component carrier(CC) index of the multiple PDCCH transmissions.
 27. The user equipmentof claim 23, wherein the processor is further configured to receivemultiple PDCCH transmissions, wherein the UCI acknowledging the multiplePDCCH transmissions is sent in a same uplink (UL) slot.
 28. The userequipment of claim 23, wherein at least two of the plurality of subsetshave different sizes.
 29. The user equipment of claim 23, wherein eachof the plurality of subsets has the same size.
 30. The user equipment ofclaim 23, wherein the implicit mapping is based on a control channelelement (CCE) index of the first PDCCH transmission.
 31. A userequipment comprising: a memory; and a processor coupled to the memory,wherein the processor is configured to: receive, from a base station, anuplink grant comprising an indication of an uplink resource to transmitan acknowledgement (ACK) and one or more downlink assignment index (DAI)bits; determine a number of bits to use to transmit the ACK based on theDAI bits; and transmit, to the base station, the ACK via the uplinkresource using the determined number of bits, wherein when the userequipment and the base station are configured with a semi-staticHARQ-ACK codebook size, a number of DAI bits is one and the one DAI bitis added to the uplink grant to indicate to the user equipment whetheror not to transmit the ACK and the number of bits are determinedaccording to the semi-static HARQ-ACK codebook size.
 32. The userequipment of claim 31, wherein to transmit the ACK comprises to transmitthe ACK on a physical uplink shared channel (PUSCH).
 33. The userequipment of claim 32, wherein when the determined number of bits is 1or 2 the ACK punctures the PUSCH, and wherein when the determined numberof bits is greater than 2 the ACK is rate matched around the PUSCH. 34.A network entity comprising: a memory; and a processor coupled to thememory, wherein the processor is configured to: transmit downlinkcontrol information (DCI) comprising one or more resource indicator (RI)bits configured to indicate to a user equipment a subset of resourcesavailable for transmitting uplink control information (UCI) in aphysical uplink control channel (PUCCH) transmission, wherein: the DCIis transmitted on one or more resources of a first physical downlinkcontrol channel (PDCCH) transmission, wherein the subset is one of aplurality of subsets, each of the plurality of subsets corresponding toa unique subset of PUCCH resources; and a number of RI bits is X,wherein a total number of PUCCH resources is Y, wherein a total numberof subsets of the PUCCH resources is 2^(∧)X, wherein (Y modulo 2^(∧)X)of the total number of subsets consist of (floor(Y/2^(∧)X)+1) PUCCHresources and any remaining of the total number of subsets consist of(floor(Y/2^(∧)X)) PUCCH resources; determine, based on the RI bits ofthe DCI, the subset of resources available for transmitting UCI in thePUCCH; identify a particular PUCCH resource within the determined subsetof resources to monitor for the UCI based on an implicit mapping ofPDCCH resources to PUCCH resources and the one or more resources of thefirst PDCCH transmission; and monitor the particular PUCCH resource forthe UCI.
 35. The network entity of claim 34, wherein the processor isfurther configured to: transmit multiple PDCCH transmissions on multiplecomponent carriers (CCs) or across multiple slots, wherein the UCIacknowledges the multiple PDCCH transmissions.
 36. The network entity ofclaim 34, wherein the processor is further configured to transmitmultiple PDCCH transmissions, wherein the first PDCCH transmission is alast transmission of the multiple PDCCH transmissions.
 37. The networkentity of claim 34, wherein the processor is further configured totransmit multiple PDCCH transmissions, wherein the first PDCCHtransmission has a smallest component carrier (CC) index of the multiplePDCCH transmissions.
 38. The network entity of claim 34, wherein theprocessor is further configured to transmit multiple PDCCHtransmissions, wherein the UCI acknowledges the multiple PDCCHtransmissions, and wherein the UCI is communicated in a same uplink (UL)slot.
 39. The network entity of claim 34, wherein at least two of theplurality of subsets have different sizes.
 40. The network entity ofclaim 34, wherein each of the plurality of subsets has the same size.41. The network entity of claim 34, wherein the implicit mapping isbased on a control channel element (CCE) index of the first PDCCHtransmission.
 42. A network entity comprising: a memory; and a processorcoupled to the memory, wherein the processor is configured to: transmit,to a user equipment, an uplink grant comprising an indication of anuplink resource to transmit an acknowledgement (ACK) and one or moredownlink assignment index (DAI) bits indicating a number of bits for theuser equipment to use to transmit the ACK; and receive, from the userequipment, the ACK via the uplink resource using the number of bits,wherein when the user equipment and the network entity are configuredwith a semi-static HARQ-ACK codebook size, a number of DAI bits is oneand the one DAI bit is added to the uplink grant to indicate to the userequipment whether or not to transmit the ACK and the number of bits aredetermined according to the semi-static HARQ-ACK codebook size.
 43. Thenetwork entity of claim 42, wherein to receive the ACK via the uplinkcomprises to receive the ACK on a physical uplink shared channel(PUSCH).
 44. The network entity of claim 43, wherein when the number ofbits is 1 or 2 the ACK punctures the PUSCH, and wherein when the numberof bits is greater than 2 the ACK is rate matched around the PUSCH.